Machine for flattening cartons

ABSTRACT

A machine for flattening cartons whereby the carton walls are erected about folding creases pre-embossed along their lower edges and whereby end sections provided on one set of mutually parallel walls are folded inwards at right angles about a vertical folding crease and their outsides can be glued to the insides of the walls which are parallel to them and whereby the ends of two mutually opposite walls are provided with folding creases extending from the lower corners of the carton to the upper edges of the walls under an angle of 45*. The machine is provided with folding devices arranged simultaneously to be moved against all four carton walls.

United States Patent [191 Kollmar 1 Feb. 12, 1974 MACHINE FORFLA'l'lENING CARTONS [75] Inventor: Ulrich Kollmar, Wurm/Pforzheim,

Germany [22] Filed: Aug. 7, 1972 [21] App]. No.: 278,502

[30] Foreign Application Priority Data Aug. 5, 1971 Germany 2139198 [52]US. Cl. 93/53 R, 93/36 R, 93/49 R [51] Int. Cl B31!) 1/52 [58] Field ofSearch. 93/36 R, 36 SQ, 49 R, 49 AC, 93/49 M, 53 R, 53 M, 53 BF, 53 AC,84 R 1,730,543 10/1929 Stortz 93/49 R 2,896,382 7/1959 Back at al.3,309,970 3/1967 Pierce 93/36 R X Primary Examiner-Granville Y. Custer,Jr. Assistant Examiner-James F. Coan Attorney, Agent, or Firm-Markva andSmith ABSTRACT A machine for flattening cartons whereby the carton wallsare erected about folding creases pre-embossed along their lower edgesand whereby end sections provided on one set of mutually parallel wallsare folded inwards at right angles about a vertical folding crease andtheir outsides can be glued to the insides of the walls which areparallel to them and whereby the ends of two mutually opposite walls areprovided with folding creases extending from the lower corners of thecarton to the upper edges of the walls under an angle of 45. The machineis provided with folding devices arranged simultaneously to be movedagainst all four carton walls.

PATENTEU FEB l 2:974

' sum 1 0r 3 PATENTEI] FEB 1 2 I974 SHEEI 2 OF 3 FIG. 3

I i Y MACHINE FOR FLATTENING CARTONS BACKGROUND OF THE INVENTION Thisinvention relates to a machine for flattening cartons.

In order to enable cartons or their parts to be stored and shipped in aspace-saving manner it is necessary to fold them flat.

The carbon elements are prepared as plane, prestamped cut-outs withpre-embossed folding creases for folding together. To begin with, thecarton walls are erected about folding creases pre-embossed along theirlower edges, and end sections provided with one set of mutually parallelwalls are folded inward at right angles about a vertical folding crease,their outside being glued to the inside of the other pair of walls whichare parallel to them.

In the course of a second operation following setting of the bondingpoints the carton walls are laid over their lower folding creasesagainst the inside of the carbon base. For this to be possible, foldingcreases leading from the lower corners of the carton to the upper edgesof the walls are provided at an angle of 45 at the ends of two mutuallyopposite walls, and the external, triangular wall sections are foldedinward about the said folding creases between the ends of the wallsforming an angle with one another.

SUMMARY OF THE INVENTION This method of flattening is very complicatedand, with cartons consisting of relatively thick cardboard, also verydifficult and strenuous. In order to avoid strains and distortions inthe carbon walls it is also necessary for all four carton walls to beflattened at the same time and for two operators to be workingsimultaneously at opposite sides of the carton. In view of the costsinvolved cheap labor has to be found for this task, but this is noteasy. Hence there is a need for a process enabling flattening of suchcartons by means of me chanical, automatic devices. An advantageoussolution of this problem is offered by the present invention.

The present invention provides a machine for flattening cartons wherebythe carton walls are erected about foldingcreases pre-embossed alongtheir lower edges and whereby end sections provided on one set ofmutually parallel walls are folded inwards at right angles about avertical folding crease and their outsides can be glued to the insidesof the walls which are parallel to them and whereby the ends of twomutually opposite walls are provided with folding creases extending fromthe lower corners of the carton to the upper edges of the walls under anangle of 45, the machine being provided with folding devices arrangedsimultaneously to be moved against all four carbon walls.

In a preferred embodiment of the machine folding devices are provided inthe shape of helical bodies rotatable on vertical spindles and furnishedwith a partial screw thread. In their initial position the said helicalbodies with the upper ends of their screw thread elements abut thecarbon walls in their direction of rotation, their screw thread elementdescending thereafter in a rear and downward direction.

When these helical bodies are rotated, their screw thread elementsinitially contact the walls of the carton laterally, and thenprogressively to an increasing extent the walls of the carton, thussimultaneously folding the latter and finally flattening them.

BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics of the machineforming the subject of the present invention and in particular thefolding devices as well as their adjustment to different carton sizesand their drive, will now be described by way of example and withreference to the accompanying drawings, in which:

FIG. 1 is a side view of a machine for flattening cartons according tothe invention;

FIG. 2 is a plan view of the machine in its initial position;

FIG. 3 is a side view of the machine elements acting direct on thecarton, in their initial positions;

FIG. 4 is a similar view of the same machine elements after partialforward movement;

FIG. 5 is a plan view of FIG. 41 showing the machine elements in thesame positions as in FIG. 4, and

FIG. 6 is a side view of an additional part of the machine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2,within a machine frame ll there is a pair of longitudinal guide rails 2which are symmetrically adjustable in respect of the verticallongitudinal centre plane 0' of the machine frame 1 in the direction ofarrows A. For this purpose, the two guide rails 2 are each provided atthe bottom near the centre of their length with a bearing 3 having afemale thread, the hand of which is in each case opposite both asregards the two bearings 3 of each rail 2 and the two rails 2. Withinthe female threads of the bearings 3 there are spindles 4 withappropriately handed male threads, whereby the centre sections of thesaid spindles 4 below the longitudinal centre plane 0 are prevented fromaxial movement so that their rotation causes the nut-type bearings 3and, as a result, the guide rails 2 to be moved symmetrically in respectof the longitudinal centre plane 0' between the rails and according totheir direction of rotation from or towards the same.

Within each guide rail 2, a pusher 5 is provided on either side of atransverse centre plane 0" of the machine, the said pusher 5 beingsymmetrically movable. For this purpose, the pushers 5 are provided withoppositely handed female threads in which in each case one half of aspindle 6 with an appropriately handed male thread is movably located,axial movement of the said spindle 6 being prevented at the transversecentre plane 0".

Each pusher 5 contains near its end facing the end of the correspondingguide rail 2 a vertical spindle 7 and near its other end a secondvertical spindle 8, the said spindles being rotatably located. Thespindles 7 and 8 may be of equal height. In the preferred embodiment,the spindle 7 is higher, and the spindle 8 is lower. A track 11corresponding to half a screw thread is in each case connected by meansof an upper and a lower, oppositely radially oriented arm 9, 10 to thehigher spindle 7, the said track 11 having a correspondingly greaterheight. Similarly, a track 14 of lesser height corresponding to half ascrew thread is connected by means of, in each case, an upper and alower arm 12, 13 with the lower spindle 8. At the same time, the highertrack 11 has a longer radius, and the lower track 14 has a shorter one.The tracks 11 and 14 may also correspond to a screw thread section ofsmaller angular range if the angular position of their arms 9, or l2,13, respectively, are appropriately selected.

The vertical spindles 7 and 8 project downward beyond the pushers 5, thesaid projections being provided with, in each case, a sprocket ofidentical diameter, an endless chain 16 being laid around the saidsprockets so that the two spindles 7 and 8 are compelled to rotate inthe same direction.

The lower ends of the tall spindles 7 are connected via a universaljoint 17 with a universal shaft 18 and the latter via a furtheruniversal joint 19 with a shaft 21 rotatably located within a verticalbearing 20 in the lower part of the machine frame 1, the said shaft 21being provided with a gearwheel 22 at its lower end. Owing to theuniversal shaft 18 and the universal joints 17 and 19 interposed withinthis section of the gearing, the longitudinal guide rails 2 and thepushers 5 guided within them can be adjusted within wide limits bothtowards and away from one another (dash-dotted position in FIG. 1). As aresult the machine with its screw thread tracks 11 and 14 can beadjusted to and used for cartons of very different sizes.

The two gearwheels 22 which are transversely opposite one another inrespect of the longitudinal centre plane 0' of the machine frame 1 (FIG.2) are in direct mutual engagement so as to rotate each other and thetracks 11 and 14 in opposite directions. The rotation which takes placein accordance with the arrows drawn in FIGS. 2 and 5 is at the same timeso arranged that the high starting section of all the tracks 11 and 14are first rotated against the peripheral walls of a carton. For thispurpose, the two gearwheels 22, which according to FIG. 2 are on thisside of the longitudinal centre plane 0 of the machine frame 1, are ingeared engagement via two mutually meshing gearwheels 23 and 24 as aresult of which the pairs of gearwheels 22 and 22 respectively locatedalong the longitudinal direction of the machine frame likewise rotate inmutually opposite directions thus bringing about the above-describedeffect of rotating the tracks 11 and 14. A drive engages at a suitablepoint of the gear system 22, 23, 24 described above.

The machine is preferably used for cartons 25 provided at the ends oftheir walls 26 located along the longitudinal edges of the guide rails 2with the sections 28 glued to the insides of the transverse walls 27,and directly behind the said sections 28 with folding creases 29ascending from the lower corners of the carton to the upper edges of thelongitudinally erect walls 26 under an angle of 45.

The machine, and in particular the tracks 11 and 14 in the manner ofscrew threads, fold, when they are rotated, all four walls 26 and 27 ofthe carton 25 about their lower folding creases against the carton base30. During this process, the small tracks 14 pass below the triangles ofwalls 27 which are separated by means of the oblique folding creases 29and cause the said triangles to be folded inward between the ends of thewalls 26 and 27 abutting the carton base 30 while being at right anglesin respect of one another. As a result the cartons 25 are flattened onall four sides simultaneously and can now be packed and shipped in aspace-saving manner. For this purpose, they are pushed from the zone ofthe flattening system by a bar 32 moved in stages by an endless chain31.

It may happen that the carton cutouts become warped as a result ofatmospheric conditions so that the carton base is not flat on the worktrack and irregularities occur during the process of folding inward. Inorder to overcome this condition each of the tall spindles 7 is providedwith an adjusting ring 33 (FIG. 6) with a low track 34 shaped in themanner of a screw thread and so arranged that it precedes the track 11.The adjusting ring 33 is provided with a perforation 35 enabling it tobe slid from above past the upper arm 9 of the track 11 unto the spindle7 and can then be adjusted by means of its track 34 at the corners ofthe carton walls at a lower height above the upper edge of the saidwalls, thus pressing the base 30 of the carton 25 flat onto the worksurface when the spindle 7 is rotated.

Various modifications of the machine are feasible. The tracks 11 and 14may be replaced by solid helical bodies consisting of a plasticmaterial, the periphery of the said body being shaped in the manner of ascrew thread in accordance with its path along the carton. The gearing22 and 24 may be replaced by a chain gear. Such modifications areclaimed as forming part of the invention.

What is claimed is:

1. A machine for flattening cartons having a base and two pairs ofmutually opposite walls erected about preembossed folding creasesprovided between said base and said walls, said walls being connected toeach other by means of end sections and one of the pairs of mutuallyopposite walls of said cartons being provided, for flattening purposes,with folding creases extending from the lower corners of the carton tothe upper edges of said one of the pair of mutually opposite walls at anangle of about 45, said machine comprising a. first and second rotatablefolding devices positioned adjacent each corner of the carton, eachdevice being constructed in the form of cam means, said devices beingarranged at two adjacent walls of a carton in the vicinity of eachcorner thereof to act simultaneously on the erected carton walls,

b. first spindles carrying said first folding devices,

c. second spindles carrying said second folding devices, and

(1. means for rotating said first and second spindles,

e. said first folding devices having a greater axial height and a largerdiameter than the second folding devices and said second folding devicesbeing positioned closer to said one of the pairs of mutually oppositewalls than said first folding devices.

2. A machine in accordance with claim 1, wherein the folding devices inthe manner of screw threads consist of solid bodies, e.g. of plasticmaterial.

3. A machine in accordance with claim 1, wherein adjusting rings open onone side and provided with helical tracks of short axial length arearranged on said first spindles so as to be adjustable above the upperedges of the corners of the carton walls and to precede the foldingdevices.

4. A machine according to claim 1 further comprising a pusher forcommonly holding the two spindles of the first and second foldingdevices disposed at each corner of the carton.

5. A machine in accordance with claim 4, wherein the pushers arearranged to be displaced in longitudinal guide rails in the longitudinaldirection of the track while the longitudinalguide rails are arranged tobe displaced at right angles to the longitudinal direction of the track,in each case symmetrically in respect of the given centre plane of themachine.

6. A machine in accordance with claim 5, wherein in each case oppositelyhanded female threads are provided in bearings attached to the twolongitudinal guide rails and in the pushers which are opposite oneanother in the longitudinal direction of the track, and spindles withappropriate male threads and prevented from axial movement at theircentre are rotatably located within the said female threads.

7. A machine in accordance with claim 4, wherein the two rotatablespindles located within a pusher are at their lower ends provided withfixed sprockets of identical diameter, an endless chain being placedabout the said sprockets.

8. A machine in accordance with claim 7, wherein the lower ends of thelong rotatable spindle are connected via a universal joint with auniversal shaft and the latter via a further universal joint with avertical shaft which carries a gearwheel.

9. A machinein accordance with claim 8, wherein the two gearwheels whichare arranged opposite one another transversely to the longitudinaldirection of the track are in direct engagement with one another.

10. A machine in accordance with claim 8, wherein the two gearwheels areprovided below one longitudinal half of the machine and are maintainedin driving engagement by two mutually meshing gearwheels, whereby adrive engages at a suitable point.

11. A machine in accordance with claim 8, wherein the shafts areconnected by sprocket gearing.

12. A machine for flattening cartons having a polygon shaped base and aplurality of side walls erected about pre-embossed folding creasesbetween said base and side walls, the ends of adjacent side walls beingjoined at each corner, at least a portion of said plurality of sidewalls including folding creases extending at an angle of about 45 fromlower corners of the carton to the upper edges thereof, said machinecomprising a. a pair of rotatably driven cam means positioned adjacenteach corner of the carton to simultaneously fold the erected cartonwalls,

b. one of each pair of cam means having a greater axial length anddiameter than the second of each pair of cam means, and

c. said second of each pair of cam means being positioned closer to oneof said side walls adjacent each corner than said one of each pair ofcam means.

1. A machine for flattening cartons having a base and two pairs of mutually opposite walls erected about pre-embossed folding creases provided between said base and said walls, said walls being connected to each other by means of end sections and one of the pairs of mutually opposite walls of said cartons being provided, for flattening purposes, with folding creases extending from the lower corners of the carton to the upper edges of said one of the pair of mutually opposite walls at an angle of about 45*, said machine comprising a. first and second rotatable folding devices positioned adjacent each corner of the carton, each device being constructed in the form of cam means, said devices being arranged at two adjacent walls of a carton in the vicinity of each corner thereof to act simultaneously on the erected carton walls, b. first spindles carrying said first folding devices, c. second spindles carrying said second folding devices, and d. means for rotating said first and second spindles, e. said first folding devices having a greater axial height and a larger diameter than the second folding devices and said second folding devices being positioned closer to said one of the pairs of mutually opposite walls than said first folding devices.
 2. A machine in accordance with claim 1, wherein the folding devices in the manner of screw threads consist of solid bodies, e.g. of plastic material.
 3. A machine in accordance with claim 1, wherein adjusting rings open on one side and provided with helical tracks of short axial length are arranged on said first spindles so as to be adjustable above the upper edges of the corners of the carton walls and to precede the folding devices.
 4. A machine according to claim 1 further comprising a pusher for commonly holding the two spindles of the first and second folding devices disposed at each corner of the carton.
 5. A machine in accordance with claim 4, wherein the pushers are arranged to be displaced in longitudinal guide rails in the longitudinal direction of the track while the longitudinal guide rails are arranged to be displaced at right angles to the longitudinal direction of the track, in each case symmetrically in respect of the given centre plane of the machine.
 6. A machine in accordance with claim 5, wherein in each case oppositely handed female threads are provided in bearings attached to the two longitudinal guide rails and in the pushers which are opposite one another in the longitudinal direction of the track, and spindles with appropriate male threads and prevented from axial movement at their centre are rotatably located within the said female threads.
 7. A machine in accordance with claim 4, wherein the two rotatable spindles located within a pusher are at their lower ends provided with fixed sprockets of identical diameter, an endless chain being placed about the said sprockets.
 8. A machine in accordance with claim 7, wherein the lower ends of the long rotatable spindle are connected via a universal joint with a universal shaft and the latter via a further universal joint with a vertical shaft which carries a gearwheel.
 9. A machine in accordance with claim 8, wherein the two gearwheels which are arranged opposite one another transversely to the longitudinal direction of the track are in direct engagement with one another.
 10. A machine in accordance with claim 8, wherein the two gearwheels are proVided below one longitudinal half of the machine and are maintained in driving engagement by two mutually meshing gearwheels, whereby a drive engages at a suitable point.
 11. A machine in accordance with claim 8, wherein the shafts are connected by sprocket gearing.
 12. A machine for flattening cartons having a polygon shaped base and a plurality of side walls erected about pre-embossed folding creases between said base and side walls, the ends of adjacent side walls being joined at each corner, at least a portion of said plurality of side walls including folding creases extending at an angle of about 45* from lower corners of the carton to the upper edges thereof, said machine comprising a. a pair of rotatably driven cam means positioned adjacent each corner of the carton to simultaneously fold the erected carton walls, b. one of each pair of cam means having a greater axial length and diameter than the second of each pair of cam means, and c. said second of each pair of cam means being positioned closer to one of said side walls adjacent each corner than said one of each pair of cam means. 